An analysis of the complementarity of ICECAP-A and EQ-5D-3 L in an adult population of patients with knee pain

• Published in: Health and quality of life outcomes 2016-03, Vol.14 (39), p.36-36, Article 36
• Main Authors: Keeley, T, Coast, J, Nicholls, E, Foster, N E, Jowett, S, Al-Janabi, H
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Care and treatment; Complications and side effects; Diagnosis; Female; Grants; Humans; Ice caps; Knee; Knee pain; Male; Middle Aged; Pain - psychology; Pain Measurement - instrumentation; Patient outcomes; Population; Quality of Life - psychology; Short Report; Surveys and Questionnaires; Tariffs
• ISSN: 1477-7525; 1477-7525
• DOI: 10.1186/s12955-016-0430-x

The ICECAP measures potentially offer a broader assessment of quality of life and well-being, in comparison to measures routinely used in economic evaluation, such as the EQ-5D-3 L. This broader assessment may allow measurement of the full effects of an intervention or treatment. Previous research has indicated that the ICECAP-O (for older people) and EQ-5D-3 L measure provide complementary information. This paper aims to determine similar information for the ICECAP-A (for the entire adult population) in terms of whether the measure is a substitute or complement to the EQ-5D-3 L. Data from the BEEP trial - a multi-centre, pragmatic, randomised controlled trial - were used. Spearman rank correlations and exploratory factor analytic methods were used to assess whether ICECAP-A and EQ-5D-3 L are measuring the same, or different, constructs. A correlation of 0.49 (p < 0.01) was found between the ICECAP-A tariff score and the EQ-5D-3 L index. Using the pooled items of the EQ-5D-3 L and the ICECAP-A a two factor solution was optimal, with the majority of EQ-5D-3 L items loading onto one factor and the majority of ICECAP-A items onto another. The results presented in this paper indicate that ICECAP-A and EQ-5D-3 L are measuring two different constructs and provide largely different, complementary information. Results showed a similarity to results presented by Davis et al. using the ICECAP-O. ISRCTN 93634563.